Superhydrophobic Artificial Compound Eye with High Transparency

Abstract

Natural compound eyes have inspired the development of self-cleaning, waterproof, and antifog optical devices. However, the traditional methods generally sacrifice the transparency of optical units to introduce hydrophobicity, which significantly limits the practical applications of state-of-the-art hydrophobic technologies. This work aims to fabricate a microimaging system by combining photolithography, inkjet printing, and chemical growth. Herein, an artificial compound eye (ACE) is endowed with stable superhydrophobicity and high transparency without affecting its optical performance. The obtained ACE system possesses good static and dynamic dewetting properties along with excellent optical performance. Its static contact angle exceeds 160°, whereas the sliding angle and contact angle hysteresis values are ∼5.5°and ∼3.8°, respectively. Furthermore, the contact time is found to be 11.97 s for the Weber number of 12. The droplet undergoes a reversible process during compressing and stretching, and the ACE exhibits no adhesion under a pressure load of 4 mN. This proves that the introduction of nonwetting nanohairs on the sidewalls of the microcone arrays significantly improves the dynamic dewetting of the system. More importantly, the properly designed position of nanohairs ensures that the optical performance of ACE is maintained at a level of ∼95% compared to that of the bare glass. The superhydrophobic ACE exhibits low adhesion and great transparency. This rationally designed ACE may provide useful guidelines for fabrication of superhydrophobic optical devices with high transparency and enable potential applications in military, medical, and some outdoor activity fields.

Self-healing system of superhydrophobic surfaces inspired from and beyond nature

“…The design and preparation of common transparent superhydrophobic coatings are inspired by the compound eye of mosquitoes. 68 Li et al 69 used photolithography to fabricate microcone arrays on the substrate, PDMS to modify the substrate with low surface energy, and inkjet printing was used to fabricate liquid microlenses in the microcone gap. Then chemical growth techniques were used to form nanoscale hair-like structures on the side walls of micron-scale conical structures to form a superhydrophobic transparent artificial compound eye (ACE).…”

Recent advances in prevailing antifogging surfaces: structures, materials, durability, and beyond

“…Furthermore, Li et al 55 fabricated hierarchical micro/nano-imaging systems by compounding photolithography, inkjet printing, and chemical growth. Specifically, this hierarchical structure is similar to the natural compound eye and lotus leaf coupling.…”

“…The appropriate structure size gives the surface antifog performance and efficaciously suppresses the reflection of light. Li et al 55 used lithography technology to obtain a microlens array on the glass substrate. The graded micro/nanostructure surface composed of the microlens array and nano-hairs has superhydrophobic and antifogging properties (contact angle >160°) (Fig.…”

Efficient Antiscaling Technology Based on Superhydrophobicity Coupled Ultrasonic Technology

“…First, the roughness of the metal surface is increased by chemical etching, photolithography, and anodization. Then, the treated metal surface is modified with low-surface-energy materials. − Studies have shown that superhydrophobic substrates immersed in the liquid phase can suppress gas on the surface to form gas layers called the plastron, which can prevent the solution from touching the surface. − As a result, there are fewer nucleation sites on the modified surface and slowing down the formation of the scale layer on the surface. The decrease in the surface energy also reduces the adhesion strength of CaCO 3 on the surface .…”